Every Cisco device has 2 sets of configurations. On routers and switches these configurations are called ‘running-config’ and ‘startup-config’ When you make any changed on a router or switch, the change applies to the running-configuration and will affect the router or switch with immediate effect. However, if the device is reloaded for whatever reason, all […]
It is advisable that on all your devices in your network, you have a disclaimer or message that appears when someone connects to your device. There have been many cases over the years where a hacker has gained access, been caught, and got away with it since there was nothing in place informing that they […]
By default a Cisco device does not have any passwords on it, so access to the console is open by default, and anyone connecting to the device is able to access privileged mode (enable mode). This of course is a security risk and one of the first things that should be done with a new […]
The console is a physical port on a Cisco device that allows us to connect to the device using a directly connected cable from your PC. It is the easiest and most reliable method of connecting to a Cisco device as it does not require configuration on the device and is enabled by default. It […]
VTY (Virtual Terminal Lines) are used when you wish to telnet into a router remotely. In order for the router to allow telnet connections, the VTY lines need to be configured with a password, which is not a default setting. If you were to try connect to a router with telnet and the VTY password […]
I’m sure you can imagine that trying to administer an IP address for every single person on the internet would be near impossible. Added to the fact that companies don’t want every computer in their network to be accessible on the internet for security reasons. The Internic and IANA (the two governing bodies for IP […]
The way that IP addresses have been used and allocated over the years has changed somewhat, however the principles have not changed. In order to better manage IP addresses they were put into classes and each class followed certain rules. In this post we are going to focus on the Class-full address structures, and understand […]
As the name indicates, and IP address is an address that computer equipment uses to be able to communicate with each other. It is made up of 4 octets (separated by a ‘.’), each of which is 8 bits in size (32 bits in total). If we look at our binary table for 8 bits, […]
Hex or Hexadecimal, is a 16-base number system with values from 0-9 as well as ABCDEF where A=10, B=11, C=12, D=13, E=14, F=15. Hex is used in many things in IT, most commonly seen in Mac addresses (A unique identity number on every Network Card). It is also seen in certain features such as HSRP […]
The first thing to get used to on a Cisco device, is how to navigate. When you first connect to the Cisco device, you will see the following Would you like to enter the initial configuration dialog? [yes/no]: In most cases, using the configuration wizard is not the best idea, so at this point you […]
The first and most important thing to understand when it comes to networking is binary. Without the fundamental understanding of binary and how it works, it would be very difficult to understand IP addresses, and without an understanding of IP addresses, it’s impossible to understand networking. So what is binary? Binary is a number system […]
Bit’s, crumbs, nibbles, bytes, megabytes ??? Ever wondered why when you buy a 250 Gigabyte hard drive and you format it, you never actually get 250 Gigabytes??? Well it’s all in the exact wording used, and how the information is reported to you. If we understand the terms of binary, and the difference between a […]